The present invention relates to the construction of a roof, basically of the flat type, with a membrane covering, there being insulation structures extending above the flat roof, with inclined surfaces having photocells thereon.
It is now conventional to produce substantially flat roofs having a structural support which is surmounted by a substrate, the substrate being substantially flat and horizontal. The substrate may be of insulating material, or it may be wood, metal, gypsum, etc. The substrate is covered with a membrane of elastomeric material which is impervious to moisture, and is resistant to deterioration from solar radiation. Such roofs, which are generally designated as "single-ply" roofs, have gained wide acceptance, and have displaced, to a large extent, the previously used flat roof construction made up of layers of asphaltsoaked material.
Single-ply roof constructions are shown in Sandqvist U.S. Pat. No. 4,074,501, Kelly U.S. Pat. No. 4,162,597 and Kelly U.S. Pat. No. 4,389,826.
Solar cells have long been proposed for generating electricity from solar radiation. The solar cells themselves are typically made of a semi-conductor material such as shown in Kohler U.S. Pat. No. 3,977,904 and Redfield U.S. Pat. No. 3,973,994. Other types of photo-cells are known. The photo-cells are typically placed in an array, electrically interconnected, and are mounted on an electrically non-conductive support member. The support member for an array of solar cells may be in the form of a tray formed from such materials as epoxy fiberglass resin, or metal, as disclosed in Lindmayer U.S. Pat. No. 4,057,439. The array or panel of photocells is typically mounted in a metal frame, which provides suitable strength for the solar cell array or panel, the metal frame itself serving as the means for mounting the module at the proper angle: see Amick U.S. Pat. No. 4,235,643 and Kurth U.S. Pat. No. 4,311,869.
It is known, also, to mount such arrays of photocells, or so called solar panels, either on free standing supports placed on the ground, or on pre-existing roofs; the panel and frame are mounted on a stand anchored to the ground, or the panel including its supporting metal frame are secured onto a completely constructed roof, as by brackets and bolts. It has been estimated that as much as one-half of the costs of a photocell panel is due to the supporting frame.
Typically, solar cells are made of silicon, which is a brittle material, the individual solar cells being in the form of discs of between about two inches and four inches diameter: see Kurth et al. U.S. Pat. No. 4,311,869. An array of photocells is held in a panel by arranging the individual photocells in rows and columns: see Klein et al. U.S. Pat. No. 4,097,308. Kohler U.S. Pat. No. 3,977,904 discloses the formation of an array of photocells on a flexible support, made up of parallel and transversely extending lenses and notches, so that it may be coiled or rolled. Further, it is known to produce an amorphous solar cell by forming a continuous flexible ribbon of photocells, which is sliced into individual photocells: see Uroshevich U.S. Pat. No. 4,383,130.
The above-noted technology has not produced a roof construction which is relatively inexpensive, which will provide for inexpensive mounting of photocells on the membrane, and which in addition will provide for the positioning of the photocell at the most effective angle for receiving radiation.